a case study in cognitive psychology

Case Study 1: A 55-Year-Old Woman With Progressive Cognitive, Perceptual, and Motor Impairments

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How Does the Examination Contribute to Our Understanding of Diagnostic Considerations? What Additional Tests or Studies Are Indicated?

Considering This Additional Data, What Would Be an Appropriate Diagnostic Formulation?

Does information about the longitudinal course of her illness alter the formulation about the most likely underlying neuropathological process, neuropathology.

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Key Study: HM’s case study (Milner and Scoville, 1957)

Travis Dixon January 29, 2019 Biological Psychology , Cognitive Psychology , Key Studies

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HM’s case study is one of the most famous and important case studies in psychology, especially in cognitive psychology. It was the source of groundbreaking new knowledge on the role of the hippocampus in memory. 

Background Info

“Localization of function in the brain” means that different parts of the brain have different functions. Researchers have discovered this from over 100 years of research into the ways the brain works. One such study was Milner’s case study on Henry Molaison.

The memory problems that HM experienced after the removal of his hippocampus provided new knowledge on the role of the hippocampus in memory formation (image: wikicommons)

At the time of the first study by Milner, HM was 29 years old. He was a mechanic who had suffered from minor epileptic seizures from when he was ten years old and began suffering severe seizures as a teenager. These may have been a result of a bike accident when he was nine. His seizures were getting worse in severity, which resulted in HM being unable to work. Treatment for his epilepsy had been unsuccessful, so at the age of 27 HM (and his family) agreed to undergo a radical surgery that would remove a part of his brain called the hippocampus . Previous research suggested that this could help reduce his seizures, but the impact it had on his memory was unexpected. The Doctor performing the radical surgery believed it was justified because of the seriousness of his seizures and the failures of other methods to treat them.

Methods and Results

In one regard, the surgery was successful as it resulted in HM experiencing less seizures. However, immediately after the surgery, the hospital staff and HM’s family noticed that he was suffering from anterograde amnesia (an inability to form new memories after the time of damage to the brain):

Here are some examples of his memory loss described in the case study:

• He could remember something if he concentrated on it, but if he broke his concentration it was lost.
• After the surgery the family moved houses. They stayed on the same street, but a few blocks away. The family noticed that HM as incapable of remembering the new address, but could remember the old one perfectly well. He could also not find his way home alone.
• He could not find objects around the house, even if they never changed locations and he had used them recently. His mother had to always show him where the lawnmower was in the garage.
• He would do the same jigsaw puzzles or read the same magazines every day, without ever apparently getting bored and realising he had read them before. (HM loved to do crossword puzzles and thought they helped him to remember words).
• He once ate lunch in front of Milner but 30 minutes later was unable to say what he had eaten, or remember even eating any lunch at all.
• When interviewed almost two years after the surgery in 1955, HM gave the date as 1953 and said his age was 27. He talked constantly about events from his childhood and could not remember details of his surgery.

Later testing also showed that he had suffered some partial retrograde amnesia (an inability to recall memories from before the time of damage to the brain). For instance, he could not remember that one of his favourite uncles passed away three years prior to his surgery or any of his time spent in hospital for his surgery. He could, however, remember some unimportant events that occurred just before his admission to the hospital.

Brenda Milner studied HM for almost 50 years – but he never remembered her.

Results continued…

His memories from events prior to 1950 (three years before his surgery), however, were fine. There was also no observable difference to his personality or to his intelligence. In fact, he scored 112 points on his IQ after the surgery, compared with 104 previously. The IQ test suggested that his ability in arithmetic had apparently improved. It seemed that the only behaviour that was affected by the removal of the hippocampus was his memory. HM was described as a kind and gentle person and this did not change after his surgery.

The Star Tracing Task

In a follow up study, Milner designed a task that would test whether or not HMs procedural memory had been affected by the surgery. He was to trace an outline of a star, but he could only see the mirrored reflection. He did this once a day over a period of a few days and Milner observed that he became faster and faster. Each time he performed the task he had no memory of ever having done it before, but his performance kept improving. This is further evidence for localization of function – the hippocampus must play a role in declarative (explicit) memory but not procedural (implicit) memory.

Cognitive psychologists have categorized memories into different types. HM’s study suggests that the hippocampus is essential for explicit (conscious) and declarative memory, but not implicit (unconscious) procedural memory.

Was his memory 100% gone? Another follow-up study

Interestingly, HM showed signs of being able to remember famous people who had only become famous after his surgery, like Lee Harvey Oswald (who assassinated JFK in 1963). (Image: wikicommons)

Another fascinating follow-up study was conducted by two researchers who wanted to see if HM had learned anything about celebrities that became famous after his surgery. At first they tested his knowledge of celebrities from before his surgery, and he knew these just as well as controls. They then showed him two names at a time, one a famous name (e.g. Liza Minelli, Lee Harvey Oswald) and the other was a name randomly taken from the phonebook. He was asked to choose the famous name and he was correct on a significant number of trials (i.e. the statistics tests suggest he wasn’t just guessing). Even more incredible was that he remembered some details about these people when asked why they were famous. For example, he could remember that Lee Harvey Oswald assassinated the president. One explanation given for the memory of these facts is that there was an emotional component. E.g. He liked these people, or the assassination was so violent, that he could remember a few details. 

HM became a hugely important case study for neuro and cognitive Psychologists. He was interviewed and tested by over 100 psychologists during the 53 years after his operation. Directly after his surgery, he lived at home with his parents as he was unable to live independently. He moved to a nursing home in 1980 and stayed there until his death in 2008. HM donated his brain to science and it was sliced into 2,401 thin slices that will be scanned and published electronically.

Critical Thinking Considerations

• How does this case study demonstrate localization of function in the brain? (e.g.c reating new long-term memories; procedural memories; storing and retrieving long term memories; intelligence; personality) ( Application )
• What are the ethical considerations involved in this study? ( Analysis )
• What are the strengths and limitations of this case study? ( Evaluation )
• Why would ongoing studies of HM be important? (Think about memory, neuroplasticity and neurogenesis) ( Analysis/Synthesis/Evaluation )
• How can findings from this case study be used to support and/or challenge the Multi-store Model of Memory? ( Application / Synthesis/Evaluation )

Exam Tips This study can be used for the following topics: Localization – the role of the hippocampus in memory Techniques to study the brain – MRI has been used to find out the exact location and size of damage to HM’s brain Bio and cognitive approach research method s – case study Bio and cognitive approach ethical considerations – anonymity Emotion and cognition – the follow-up study on HM and memories of famous people could be used in an essay to support the idea that emotion affects memory Models of memory – the multi-store model : HM’s study provides evidence for the fact that our memories all aren’t formed and stored in one place but travel from store to store (because his transfer from STS to LTS was damaged – if it was all in one store this specific problem would not occur)

Milner, Brenda. Scoville, William Beecher. “Loss of Recent Memory after Bilateral Hippocampal Lesions”. The Journal of Neurology, Neurosurgery and Psychiatry. 1957; 20: 11 21. (Accessed from web.mit.edu )

The man who couldn’t remember”. nova science now. an interview with brenda corkin . 06.01.2009.       .

  Here’s a good video recreation documentary of HM’s case study…

Travis Dixon is an IB Psychology teacher, author, workshop leader, examiner and IA moderator.

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Olfactory memory: a case study in cognitive psychology

Affiliation.

• 1 Department of Psychology, University of Ulster, Northern Ireland.
• PMID: 8667286
• DOI: 10.1080/00223980.1996.9915012

Over the last decade, interest in the general applicability of psychological research has increased significantly, leading to doubts among some critics of cognitive psychology regarding the usefulness of the modern information-processing approach. In particular, current cognitive models of memory address mainly visual and verbal information processing, with little acknowledgement of the existence of other sensory modalities. However, since the mid-1970's, the literature on olfactory memory has expanded rapidly, and it has remained relatively independent of mainstream memory research. This article outlines the olfactory literature, which has focused principally on examination of the Proustian characteristics of smell. The relationship between olfactory and other types of memory is also examined. The author notes that there is evidence that models of memory intended to be general have taken insufficient account of findings from olfaction and other sensory modalities, an approach that could be considered symptomatic of dangerous tendency to base purportedly general theories on databases that are too narrow.

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Case Study Research Method in Psychology

Saul McLeod, PhD

Editor-in-Chief for Simply Psychology

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Saul McLeod, PhD., is a qualified psychology teacher with over 18 years of experience in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.

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Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.

On This Page:

Case studies are in-depth investigations of a person, group, event, or community. Typically, data is gathered from various sources using several methods (e.g., observations & interviews).

The case study research method originated in clinical medicine (the case history, i.e., the patient’s personal history). In psychology, case studies are often confined to the study of a particular individual.

The information is mainly biographical and relates to events in the individual’s past (i.e., retrospective), as well as to significant events that are currently occurring in his or her everyday life.

The case study is not a research method, but researchers select methods of data collection and analysis that will generate material suitable for case studies.

Freud (1909a, 1909b) conducted very detailed investigations into the private lives of his patients in an attempt to both understand and help them overcome their illnesses.

This makes it clear that the case study is a method that should only be used by a psychologist, therapist, or psychiatrist, i.e., someone with a professional qualification.

There is an ethical issue of competence. Only someone qualified to diagnose and treat a person can conduct a formal case study relating to atypical (i.e., abnormal) behavior or atypical development.

 Famous Case Studies

• Anna O – One of the most famous case studies, documenting psychoanalyst Josef Breuer’s treatment of “Anna O” (real name Bertha Pappenheim) for hysteria in the late 1800s using early psychoanalytic theory.
• Little Hans – A child psychoanalysis case study published by Sigmund Freud in 1909 analyzing his five-year-old patient Herbert Graf’s house phobia as related to the Oedipus complex.
• Bruce/Brenda – Gender identity case of the boy (Bruce) whose botched circumcision led psychologist John Money to advise gender reassignment and raise him as a girl (Brenda) in the 1960s.
• Genie Wiley – Linguistics/psychological development case of the victim of extreme isolation abuse who was studied in 1970s California for effects of early language deprivation on acquiring speech later in life.
• Phineas Gage – One of the most famous neuropsychology case studies analyzes personality changes in railroad worker Phineas Gage after an 1848 brain injury involving a tamping iron piercing his skull.

Clinical Case Studies

• Studying the effectiveness of psychotherapy approaches with an individual patient
• Assessing and treating mental illnesses like depression, anxiety disorders, PTSD
• Neuropsychological cases investigating brain injuries or disorders

Child Psychology Case Studies

• Studying psychological development from birth through adolescence
• Cases of learning disabilities, autism spectrum disorders, ADHD
• Effects of trauma, abuse, deprivation on development

Types of Case Studies

• Explanatory case studies : Used to explore causation in order to find underlying principles. Helpful for doing qualitative analysis to explain presumed causal links.
• Exploratory case studies : Used to explore situations where an intervention being evaluated has no clear set of outcomes. It helps define questions and hypotheses for future research.
• Descriptive case studies : Describe an intervention or phenomenon and the real-life context in which it occurred. It is helpful for illustrating certain topics within an evaluation.
• Multiple-case studies : Used to explore differences between cases and replicate findings across cases. Helpful for comparing and contrasting specific cases.
• Intrinsic : Used to gain a better understanding of a particular case. Helpful for capturing the complexity of a single case.
• Collective : Used to explore a general phenomenon using multiple case studies. Helpful for jointly studying a group of cases in order to inquire into the phenomenon.

Where Do You Find Data for a Case Study?

There are several places to find data for a case study. The key is to gather data from multiple sources to get a complete picture of the case and corroborate facts or findings through triangulation of evidence. Most of this information is likely qualitative (i.e., verbal description rather than measurement), but the psychologist might also collect numerical data.

1. Primary sources

• Interviews – Interviewing key people related to the case to get their perspectives and insights. The interview is an extremely effective procedure for obtaining information about an individual, and it may be used to collect comments from the person’s friends, parents, employer, workmates, and others who have a good knowledge of the person, as well as to obtain facts from the person him or herself.
• Observations – Observing behaviors, interactions, processes, etc., related to the case as they unfold in real-time.
• Documents & Records – Reviewing private documents, diaries, public records, correspondence, meeting minutes, etc., relevant to the case.

2. Secondary sources

• News/Media – News coverage of events related to the case study.
• Academic articles – Journal articles, dissertations etc. that discuss the case.
• Government reports – Official data and records related to the case context.
• Books/films – Books, documentaries or films discussing the case.

3. Archival records

Searching historical archives, museum collections and databases to find relevant documents, visual/audio records related to the case history and context.

Public archives like newspapers, organizational records, photographic collections could all include potentially relevant pieces of information to shed light on attitudes, cultural perspectives, common practices and historical contexts related to psychology.

4. Organizational records

Organizational records offer the advantage of often having large datasets collected over time that can reveal or confirm psychological insights.

Of course, privacy and ethical concerns regarding confidential data must be navigated carefully.

However, with proper protocols, organizational records can provide invaluable context and empirical depth to qualitative case studies exploring the intersection of psychology and organizations.

• Organizational/industrial psychology research : Organizational records like employee surveys, turnover/retention data, policies, incident reports etc. may provide insight into topics like job satisfaction, workplace culture and dynamics, leadership issues, employee behaviors etc.
• Clinical psychology : Therapists/hospitals may grant access to anonymized medical records to study aspects like assessments, diagnoses, treatment plans etc. This could shed light on clinical practices.
• School psychology : Studies could utilize anonymized student records like test scores, grades, disciplinary issues, and counseling referrals to study child development, learning barriers, effectiveness of support programs, and more.

How do I Write a Case Study in Psychology?

Follow specified case study guidelines provided by a journal or your psychology tutor. General components of clinical case studies include: background, symptoms, assessments, diagnosis, treatment, and outcomes. Interpreting the information means the researcher decides what to include or leave out. A good case study should always clarify which information is the factual description and which is an inference or the researcher’s opinion.

1. Introduction

• Provide background on the case context and why it is of interest, presenting background information like demographics, relevant history, and presenting problem.
• Compare briefly to similar published cases if applicable. Clearly state the focus/importance of the case.

2. Case Presentation

• Describe the presenting problem in detail, including symptoms, duration,and impact on daily life.
• Include client demographics like age and gender, information about social relationships, and mental health history.
• Describe all physical, emotional, and/or sensory symptoms reported by the client.
• Use patient quotes to describe the initial complaint verbatim. Follow with full-sentence summaries of relevant history details gathered, including key components that led to a working diagnosis.
• Summarize clinical exam results, namely orthopedic/neurological tests, imaging, lab tests, etc. Note actual results rather than subjective conclusions. Provide images if clearly reproducible/anonymized.
• Clearly state the working diagnosis or clinical impression before transitioning to management.

3. Management and Outcome

• Indicate the total duration of care and number of treatments given over what timeframe. Use specific names/descriptions for any therapies/interventions applied.
• Present the results of the intervention,including any quantitative or qualitative data collected.
• For outcomes, utilize visual analog scales for pain, medication usage logs, etc., if possible. Include patient self-reports of improvement/worsening of symptoms. Note the reason for discharge/end of care.

4. Discussion

• Analyze the case, exploring contributing factors, limitations of the study, and connections to existing research.
• Analyze the effectiveness of the intervention,considering factors like participant adherence, limitations of the study, and potential alternative explanations for the results.
• Identify any questions raised in the case analysis and relate insights to established theories and current research if applicable. Avoid definitive claims about physiological explanations.
• Offer clinical implications, and suggest future research directions.

5. Additional Items

• Thank specific assistants for writing support only. No patient acknowledgments.
• References should directly support any key claims or quotes included.
• Use tables/figures/images only if substantially informative. Include permissions and legends/explanatory notes.
• Provides detailed (rich qualitative) information.
• Provides insight for further research.
• Permitting investigation of otherwise impractical (or unethical) situations.

Case studies allow a researcher to investigate a topic in far more detail than might be possible if they were trying to deal with a large number of research participants (nomothetic approach) with the aim of ‘averaging’.

Because of their in-depth, multi-sided approach, case studies often shed light on aspects of human thinking and behavior that would be unethical or impractical to study in other ways.

Research that only looks into the measurable aspects of human behavior is not likely to give us insights into the subjective dimension of experience, which is important to psychoanalytic and humanistic psychologists.

Case studies are often used in exploratory research. They can help us generate new ideas (that might be tested by other methods). They are an important way of illustrating theories and can help show how different aspects of a person’s life are related to each other.

The method is, therefore, important for psychologists who adopt a holistic point of view (i.e., humanistic psychologists ).

Limitations

• Lacking scientific rigor and providing little basis for generalization of results to the wider population.
• Researchers’ own subjective feelings may influence the case study (researcher bias).
• Difficult to replicate.
• Time-consuming and expensive.
• The volume of data, together with the time restrictions in place, impacted the depth of analysis that was possible within the available resources.

Because a case study deals with only one person/event/group, we can never be sure if the case study investigated is representative of the wider body of “similar” instances. This means the conclusions drawn from a particular case may not be transferable to other settings.

Because case studies are based on the analysis of qualitative (i.e., descriptive) data , a lot depends on the psychologist’s interpretation of the information she has acquired.

This means that there is a lot of scope for Anna O , and it could be that the subjective opinions of the psychologist intrude in the assessment of what the data means.

For example, Freud has been criticized for producing case studies in which the information was sometimes distorted to fit particular behavioral theories (e.g., Little Hans ).

This is also true of Money’s interpretation of the Bruce/Brenda case study (Diamond, 1997) when he ignored evidence that went against his theory.

Breuer, J., & Freud, S. (1895).  Studies on hysteria . Standard Edition 2: London.

Curtiss, S. (1981). Genie: The case of a modern wild child .

Diamond, M., & Sigmundson, K. (1997). Sex Reassignment at Birth: Long-term Review and Clinical Implications. Archives of Pediatrics & Adolescent Medicine , 151(3), 298-304

Freud, S. (1909a). Analysis of a phobia of a five year old boy. In The Pelican Freud Library (1977), Vol 8, Case Histories 1, pages 169-306

Freud, S. (1909b). Bemerkungen über einen Fall von Zwangsneurose (Der “Rattenmann”). Jb. psychoanal. psychopathol. Forsch ., I, p. 357-421; GW, VII, p. 379-463; Notes upon a case of obsessional neurosis, SE , 10: 151-318.

Harlow J. M. (1848). Passage of an iron rod through the head.  Boston Medical and Surgical Journal, 39 , 389–393.

Harlow, J. M. (1868).  Recovery from the Passage of an Iron Bar through the Head .  Publications of the Massachusetts Medical Society. 2  (3), 327-347.

Money, J., & Ehrhardt, A. A. (1972).  Man & Woman, Boy & Girl : The Differentiation and Dimorphism of Gender Identity from Conception to Maturity. Baltimore, Maryland: Johns Hopkins University Press.

Money, J., & Tucker, P. (1975). Sexual signatures: On being a man or a woman.

Further Information

• Case Study Approach
• Case Study Method
• Enhancing the Quality of Case Studies in Health Services Research
• “We do things together” A case study of “couplehood” in dementia
• Using mixed methods for evaluating an integrative approach to cancer care: a case study

Cognitive Psychology: Experiments & Examples

Cognitive psychology reveals, for example, insights into how we think, reason, learn, remember, produce language and even how illogical our brains are.

Fifty years ago there was a revolution in cognitive psychology which changed the way we think about the mind.

The ‘cognitive revolution’ inspired cognitive psychologists to start thinking of the mind as a kind of organic computer, rather than as an impenetrable black box which would never be understood.

This metaphor has motivated cognitive psychology to investigate the software central to our everyday functioning, opening the way to insights into how we think, reason, learn, remember and produce language.

Here are 10 classic examples of cognitive psychology studies that have helped reveal how thinking works.

1. Cognitive psychology reveals how experts think

Without experts the human race would be sunk.

But what is it about how experts think which lets them achieve breakthroughs which we can all enjoy?

The answer is in how experts think about problems, compared with novices, cognitive psychology reveals.

That’s what Chi et al. (1981) found when they compared how experts and novices represented physics problems.

Novices tended to get stuck thinking about the surface details of the problem whereas experts saw the underlying principles that were operating.

It was partly this deeper, abstract way of approaching problems that made the experts more successful.

2. Short-term memory lasts 15-30 seconds

Short-term memory is a lot shorter than many think, cognitive psychologists find.

In fact it lasts about 15-30 seconds.

We know that because of a classic cognitive psychology study carried out by Lloyd and Margaret Peterson ( Peterson & Peterson, 1959 ).

Participants had to try and remember and recall three-letter strings, like FZX.

When tested, after 3 seconds they could recall 80 percent of them, after 18 seconds, though, they could only remember 10 percent.

That’s how short-term short-term memory is.

3. Cognitive psychology finds people are not logical

People find formal logic extremely difficult to cope with–that’s normal, cognitive psychology finds.

Here’s a quick test for you, and don’t be surprised if your brain overheats:

“You are shown a set of four cards placed on a table, each of which has a number on one side and a coloured patch on the other side. The visible faces of the cards show 3, 8, red and brown. Which card(s) must you turn over in order to test the truth of the proposition that if a card shows an even number on one face, then its opposite face is red?”

The answer is you have to turn over the ‘8’ and the brown card (for an explanation search for “Wason selection task” — even after hearing it, many people still can’t believe this is the correct answer).

If you got it right, then you’re in the minority (or you’ve seen the test before!).

When Wason conducted this classic experiment, less than 10 percent of people got it right (Wason, 1968).

Cognitive psychology finds that our brains are not set up for this kind of formal logic.

4. Example: framing in cognitive psychology

The way you frame a problem, argument or statement can have huge effects on how people perceive it.

For example, think about risk for a moment and the fact that people don’t like to take chances.

They dislike taking chances so much that even the whiff of negativity is enough to send people running for the hills.

That’s what cognitive psychologists Kahneman and Tversky (1981) demonstrated when they asked participants to imagine 600 people were affected by a deadly disease.

There was, they were told, a treatment, but it is risky.

If you decided to use the treatment, here are the odds:

“A 33% chance of saving all 600 people, 66% possibility of saving no one.”

When told this, 72 percent of people thought it was a good bet.

But, when presented the problem this way:

“A 33% chance that no people will die, 66% probability that all 600 will die.”

…the number choosing it dropped to 22 percent.

The beauty of the study is that the outcomes are identical, it’s just the framing that’s different.

Cognitive psychology shows that the way we think is heavily influenced by the terms in which issues are expressed.

5. Attention is like a spotlight

We actually have two sets of eyes — one set real and one virtual, cognitive psychology finds.

We have the real eyes moving around in their sockets, but we also have ‘virtual eyes’ looking around our field of vision, choosing what we pay attention to.

People are using their virtual eyes all the time: for example, when they watch each other using their peripheral vision.

You don’t need to look directly at an attractive stranger to eye them up, you can look ‘out of the corner of your eye’.

Cognitive psychologists have called this the ‘spotlight of attention’ and studies have actually measured its movement.

It means we can notice things in the fraction of a second before our eyes have a chance to reorient.

→ Read on: The Attentional Spotlight

6. The cocktail party effect in cognitive psychology

It’s not just vision which has a kind of spotlight, our hearing is also finely tuned, cognitive psychologists have discovered.

It’s like when you’re at a cocktail party and you can tune out all the voices, except the person you’re talking to.

Or, you can tune out the person you’re talking to and eavesdrop on a more interesting conversation behind.

A beautiful cognitive psychology demonstration of this was carried out in the 1950s by Cherry (1953) .

He found that people could even distinguish the same voice reading two different messages at the same time.

→ Read on: The Cocktail Party Effect

7. Children’s cognitive psychology example

If you take a toy duck and show it to a 12-month-old infant, then put your hand under a cushion, leave the duck there and bring your hand out, the child will only look in your hand, almost never under the cushion.

At this age, children behave as though things they can’t see don’t even exist.

As the famous child psychologist Jean Piaget noted:

“The child’s universe is still only a totality of pictures emerging from nothingness at the moment of action, to return to nothingness at the moment when the action is finished.”

And yet, just six months later, a child will typically look under the cushion, studies in cognitive psychology have found.

It has learnt that things that are hidden from view can continue to exist — this is known as object permanence .

This is just one miracle amongst many in developmental  psychology and cognitive psychology.

8. The McGurk effect in cognitive psychology

The brain is integrating information from all our senses to produce our experience, cognitive psychology shows.

This is brilliantly revealed by the McGurk effect ( McGurk & MacDonald, 1976 ).

Watch the following clip from a BBC documentary to see the effect in full.

You won’t believe it until you see and hear it yourself.

The sensation is quite odd:

9. Implanting false memories

People sometimes think of their memories as being laid down, then later either recalled or forgotten, with little change in the memories themselves between the two.

In fact, cognitive psychology shows that the reality is much more complex and, in some cases, alarming.

One of the most dramatic examples of these studies demonstrated that memories can be changed, or even implanted later, was carried out by Elizabeth Loftus.

In her study, a childhood memory of being lost in a mall was successfully implanted in some people’s mind, despite their families confirming nothing like it had ever happened to them.

Later research in cognitive psychology have found that 50 percent of participants could have a false memory successfully implanted.

→ Read on: Implanting False Memories

10. Why the incompetent don’t know they’re incompetent

There all kinds of cognitive biases operating in the mind, cognitive psychology has found.

The Dunning-Kruger effect , though, is a favourite because it explains why incompetent people don’t know they’re incompetent.

David Dunning and Justin Kruger found in their studies that people who are the most incompetent are the least aware of their own incompetence.

At the other end of the scale, the most competent are most aware of their own shortcomings.

→ Explore more: Cognitive Biases : Why We Make Irrational Decisions

Author: Dr Jeremy Dean

Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology. He has been writing about scientific research on PsyBlog since 2004. View all posts by Dr Jeremy Dean

Join the free PsyBlog mailing list. No spam, ever.

Case Example: Jill, a 32-year-old Afghanistan War Veteran

This case example explains how Jill's therapist used a cognitive intervention with a written worksheet as a starting point for engaging in Socratic dialogue. 

About this Example

Jill's Story

Jill, a 32-year-old Afghanistan war veteran, had been experiencing PTSD symptoms for more than five years. She consistently avoided thoughts and images related to witnessing her fellow service members being hit by an improvised explosive device (IED) while driving a combat supply truck. Over the years, Jill became increasingly depressed and began using alcohol on a daily basis to help assuage her PTSD symptoms. She had difficulties in her employment, missing many days of work, and she reported feeling disconnected and numb around her husband and children. In addition to a range of other PTSD symptoms, Jill had a recurring nightmare of the event in which she was the leader of a convoy and her lead truck broke down. She waved the second truck forward, the truck that hit the IED, while she and her fellow service members on the first truck worked feverishly to repair it. Consistent with the traumatic event, her nightmare included images of her and the service members on the first truck smiling and waving at those on the second truck, and the service members on the second truck making fun of the broken truck and their efforts to fix it — “Look at that piece of junk truck — good luck getting that clunker fixed.”

After a thorough assessment of her PTSD and comorbid symptoms, psychoeducation about PTSD symptoms, and a rationale for using trauma focused cognitive interventions, Jill received 10 sessions of cognitive therapy for PTSD. She was first assigned cognitive worksheets to begin self-monitoring events, her thoughts about these events, and consequent feelings. These worksheets were used to sensitize Jill to the types of cognitions that she was having about current day events and to appraisals that she had about the explosion. For example, one of the thoughts she recorded related to the explosion was, “I should have had them wait and not had them go on.” She recorded her related feeling to be guilt. Jill’s therapist used this worksheet as a starting point for engaging in Socratic dialogue, as shown in the following example:

Therapist: Jill, do you mind if I ask you a few questions about this thought that you noticed, “I should have had them wait and not had them go on?”

Client: Sure.

Therapist: Can you tell me what the protocol tells you to do in a situation in which a truck breaks down during a convoy?

Client: You want to get the truck repaired as soon as possible, because the point of a convoy is to keep the trucks moving so that you aren’t sitting ducks.

Therapist: The truck that broke down was the lead truck that you were on. What is the protocol in that case?

Client: The protocol says to wave the other trucks through and keep them moving so that you don’t have multiple trucks just sitting there together more vulnerable.

Therapist: Okay. That’s helpful for me to understand. In light of the protocol you just described and the reasons for it, why do you think you should have had the second truck wait and not had them go on?

Client: If I hadn’t have waved them through and told them to carry on, this wouldn’t have happened. It is my fault that they died. (Begins to cry)

Therapist: (Pause) It is certainly sad that they died. (Pause) However, I want us to think through the idea that you should have had them wait and not had them go on, and consequently that it was your fault. (Pause) If you think back about what you knew at the time — not what you know now 5 years after the outcome — did you see anything that looked like a possible explosive device when you were scanning the road as the original lead truck?

Client: No. Prior to the truck breaking down, there was nothing that we noticed. It was an area of Iraq that could be dangerous, but there hadn’t been much insurgent activity in the days and weeks prior to it happening.

Therapist: Okay. So, prior to the explosion, you hadn’t seen anything suspicious.

Client: No.

Therapist: When the second truck took over as the lead truck, what was their responsibility and what was your responsibility at that point?

Client: The next truck that Mike and my other friends were on essentially became the lead truck, and I was responsible for trying to get my truck moving again so that we weren’t in danger.

Therapist: Okay. In that scenario then, would it be Mike and the others’ jobs to be scanning the environment ahead for potential dangers?

Client: Yes, but I should have been able to see and warn them.

Therapist: Before we determine that, how far ahead of you were Mike and the others when the explosion occurred?

Client: Oh (pause), probably 200 yards?

Therapist: 200 yards—that’s two football fields’ worth of distance, right?

Client: Right.

Therapist: You’ll have to educate me. Are there explosive devices that you wouldn’t be able to detect 200 yards ahead?

Client: Absolutely.

Therapist: How about explosive devices that you might not see 10 yards ahead?

Client: Sure. If they are really good, you wouldn’t see them at all.

Therapist: So, in light of the facts that you didn’t see anything at the time when you waved them through at 200 yards behind and that they obviously didn’t see anything 10 yards ahead before they hit the explosion, and that protocol would call for you preventing another danger of being sitting ducks, help me understand why you wouldn’t have waved them through at that time? Again, based on what you knew at the time?

Client: (Quietly) I hadn’t thought about the fact that Mike and the others obviously didn’t see the device at 10 yards, as you say, or they would have probably done something else. (Pause) Also, when you say that we were trying to prevent another danger at the time of being “sitting ducks,” it makes me feel better about waving them through.

Therapist: Can you describe the type of emotion you have when you say, “It makes me feel better?”

Client: I guess I feel less guilty.

Therapist: That makes sense to me. As we go back and more accurately see the reality of what was really going on at the time of this explosion, it is important to notice that it makes you feel better emotionally. (Pause) In fact, I was wondering if you had ever considered that, in this situation, you actually did exactly what you were supposed to do and that something worse could have happened had you chosen to make them wait?

Client: No. I haven’t thought about that.

Therapist: Obviously this was an area that insurgents were active in if they were planting explosives. Is it possible that it could have gone down worse had you chosen not to follow protocol and send them through?

Client: Hmmm. I hadn’t thought about that either.

Therapist: That’s okay. Many people don’t think through what could have happened if they had chosen an alternative course of action at the time or they assume that there would have only been positive outcomes if they had done something different. I call it “happily ever after” thinking — assuming that a different action would have resulted in a positive outcome. (Pause) When you think, “I did a good job following protocol in a stressful situation that may have prevented more harm from happening,” how does that make you feel?

Client: It definitely makes me feel less guilty.

Therapist: I’m wondering if there is any pride that you might feel?

Client: Hmmm...I don’t know if I can go that far.

Therapist: What do you mean?

Client: It seems wrong to feel pride when my friends died.

Therapist: Is it possible to feel both pride and sadness in this situation? (Pause) Do you think Mike would hold it against you for feeling pride, as well as sadness for his and others’ losses?

Client: Mike wouldn’t hold it against me. In fact, he’d probably reassure me that I did a good job.

Therapist: (Pause) That seems really important for you to remember. It may be helpful to remind yourself of what you have discovered today, because you have some habits in thinking about this event in a particular way. We are also going to be doing some practice assignments that will help to walk you through your thoughts about what happened during this event, help you to remember what you knew at the time, and remind you how different thoughts can result in different feelings about what happened.

Client: I actually feel a bit better after this conversation. 

Another thought that Jill described in relation to the traumatic event was, “I should have seen the explosion was going to happen to prevent my friends from dying.” Her related feelings were guilt and self-directed anger. The therapist used this thought to introduce the cognitive intervention of "challenging thoughts" and provided a worksheet for practice. The therapist first provided education about the different types of thinking errors, including habitual thinking, all-or-none thinking, taking things out of context, overestimating probabilities, and emotional reasoning, as well as discussing other important factors, such as gathering evidence for and against the thought, evaluating the source of the information, and focusing on irrelevant factors. 

More specifically, Jill noted that she experienced 100 percent intensity of guilt and 75 percent intensity of anger at herself in relation to the thought "I should have seen the explosive device to prevent my friends from dying." She posed several challenging questions, including the notion that improvised explosive devices are meant to be concealed, that she is the source of the information (because others don't blame her), and that her feelings are not based on facts (i.e., she feels guilt and therefore must be guilty). She came up with the alternative thought, "The best explosive devices aren't seen and Mike (driver of the second truck) was a good soldier. If he saw something he would stopped or tried to evade it," which she rated as 90 percent confidence in believing. She consequently believed her original thought 10 percent, and re-rated her emotions as only 10 percent guilt and 5 percent anger at self.

Treating PTSD with cognitive-behavioral therapies: Interventions that work

This case example is reprinted with permission from: Monson, C. M. & Shnaider, P. (2014). Treating PTSD with cognitive-behavioral therapies: Interventions that work . Washington, DC: American Psychological Association. 

Other Case Examples

• Cognitive Therapy Philip, a 60-year-old who was in a traffic accident (PDF, 294KB)
• Eye Movement Desensitization and Reprocessing Mike, a 32-year-old Iraq War Veteran
• Narrative Exposure Therapy Eric, a 24-year-old Rwandan refugee living in Uganda (PDF, 28KB)
• Prolonged Exposure Terry, a 42-year-old earthquake survivor

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What Is a Case Study?

Weighing the pros and cons of this method of research

Verywell / Colleen Tighe

• Pros and Cons

What Types of Case Studies Are Out There?

Where do you find data for a case study, how do i write a psychology case study.

A case study is an in-depth study of one person, group, or event. In a case study, nearly every aspect of the subject's life and history is analyzed to seek patterns and causes of behavior. Case studies can be used in many different fields, including psychology, medicine, education, anthropology, political science, and social work.

The point of a case study is to learn as much as possible about an individual or group so that the information can be generalized to many others. Unfortunately, case studies tend to be highly subjective, and it is sometimes difficult to generalize results to a larger population.

While case studies focus on a single individual or group, they follow a format similar to other types of psychology writing. If you are writing a case study, we got you—here are some rules of APA format to reference.  

At a Glance

A case study, or an in-depth study of a person, group, or event, can be a useful research tool when used wisely. In many cases, case studies are best used in situations where it would be difficult or impossible for you to conduct an experiment. They are helpful for looking at unique situations and allow researchers to gather a lot of˜ information about a specific individual or group of people. However, it's important to be cautious of any bias we draw from them as they are highly subjective.

What Are the Benefits and Limitations of Case Studies?

A case study can have its strengths and weaknesses. Researchers must consider these pros and cons before deciding if this type of study is appropriate for their needs.

One of the greatest advantages of a case study is that it allows researchers to investigate things that are often difficult or impossible to replicate in a lab. Some other benefits of a case study:

• Allows researchers to capture information on the 'how,' 'what,' and 'why,' of something that's implemented
• Gives researchers the chance to collect information on why one strategy might be chosen over another
• Permits researchers to develop hypotheses that can be explored in experimental research

On the other hand, a case study can have some drawbacks:

• It cannot necessarily be generalized to the larger population
• Cannot demonstrate cause and effect
• It may not be scientifically rigorous
• It can lead to bias

Researchers may choose to perform a case study if they want to explore a unique or recently discovered phenomenon. Through their insights, researchers develop additional ideas and study questions that might be explored in future studies.

It's important to remember that the insights from case studies cannot be used to determine cause-and-effect relationships between variables. However, case studies may be used to develop hypotheses that can then be addressed in experimental research.

Case Study Examples

There have been a number of notable case studies in the history of psychology. Much of  Freud's work and theories were developed through individual case studies. Some great examples of case studies in psychology include:

• Anna O : Anna O. was a pseudonym of a woman named Bertha Pappenheim, a patient of a physician named Josef Breuer. While she was never a patient of Freud's, Freud and Breuer discussed her case extensively. The woman was experiencing symptoms of a condition that was then known as hysteria and found that talking about her problems helped relieve her symptoms. Her case played an important part in the development of talk therapy as an approach to mental health treatment.
• Phineas Gage : Phineas Gage was a railroad employee who experienced a terrible accident in which an explosion sent a metal rod through his skull, damaging important portions of his brain. Gage recovered from his accident but was left with serious changes in both personality and behavior.
• Genie : Genie was a young girl subjected to horrific abuse and isolation. The case study of Genie allowed researchers to study whether language learning was possible, even after missing critical periods for language development. Her case also served as an example of how scientific research may interfere with treatment and lead to further abuse of vulnerable individuals.

Such cases demonstrate how case research can be used to study things that researchers could not replicate in experimental settings. In Genie's case, her horrific abuse denied her the opportunity to learn a language at critical points in her development.

This is clearly not something researchers could ethically replicate, but conducting a case study on Genie allowed researchers to study phenomena that are otherwise impossible to reproduce.

There are a few different types of case studies that psychologists and other researchers might use:

• Collective case studies : These involve studying a group of individuals. Researchers might study a group of people in a certain setting or look at an entire community. For example, psychologists might explore how access to resources in a community has affected the collective mental well-being of those who live there.
• Descriptive case studies : These involve starting with a descriptive theory. The subjects are then observed, and the information gathered is compared to the pre-existing theory.
• Explanatory case studies : These   are often used to do causal investigations. In other words, researchers are interested in looking at factors that may have caused certain things to occur.
• Exploratory case studies : These are sometimes used as a prelude to further, more in-depth research. This allows researchers to gather more information before developing their research questions and hypotheses .
• Instrumental case studies : These occur when the individual or group allows researchers to understand more than what is initially obvious to observers.
• Intrinsic case studies : This type of case study is when the researcher has a personal interest in the case. Jean Piaget's observations of his own children are good examples of how an intrinsic case study can contribute to the development of a psychological theory.

The three main case study types often used are intrinsic, instrumental, and collective. Intrinsic case studies are useful for learning about unique cases. Instrumental case studies help look at an individual to learn more about a broader issue. A collective case study can be useful for looking at several cases simultaneously.

The type of case study that psychology researchers use depends on the unique characteristics of the situation and the case itself.

There are a number of different sources and methods that researchers can use to gather information about an individual or group. Six major sources that have been identified by researchers are:

• Archival records : Census records, survey records, and name lists are examples of archival records.
• Direct observation : This strategy involves observing the subject, often in a natural setting . While an individual observer is sometimes used, it is more common to utilize a group of observers.
• Documents : Letters, newspaper articles, administrative records, etc., are the types of documents often used as sources.
• Interviews : Interviews are one of the most important methods for gathering information in case studies. An interview can involve structured survey questions or more open-ended questions.
• Participant observation : When the researcher serves as a participant in events and observes the actions and outcomes, it is called participant observation.
• Physical artifacts : Tools, objects, instruments, and other artifacts are often observed during a direct observation of the subject.

If you have been directed to write a case study for a psychology course, be sure to check with your instructor for any specific guidelines you need to follow. If you are writing your case study for a professional publication, check with the publisher for their specific guidelines for submitting a case study.

Here is a general outline of what should be included in a case study.

Section 1: A Case History

This section will have the following structure and content:

Background information : The first section of your paper will present your client's background. Include factors such as age, gender, work, health status, family mental health history, family and social relationships, drug and alcohol history, life difficulties, goals, and coping skills and weaknesses.

Description of the presenting problem : In the next section of your case study, you will describe the problem or symptoms that the client presented with.

Describe any physical, emotional, or sensory symptoms reported by the client. Thoughts, feelings, and perceptions related to the symptoms should also be noted. Any screening or diagnostic assessments that are used should also be described in detail and all scores reported.

Your diagnosis : Provide your diagnosis and give the appropriate Diagnostic and Statistical Manual code. Explain how you reached your diagnosis, how the client's symptoms fit the diagnostic criteria for the disorder(s), or any possible difficulties in reaching a diagnosis.

Section 2: Treatment Plan

This portion of the paper will address the chosen treatment for the condition. This might also include the theoretical basis for the chosen treatment or any other evidence that might exist to support why this approach was chosen.

• Cognitive behavioral approach : Explain how a cognitive behavioral therapist would approach treatment. Offer background information on cognitive behavioral therapy and describe the treatment sessions, client response, and outcome of this type of treatment. Make note of any difficulties or successes encountered by your client during treatment.
• Humanistic approach : Describe a humanistic approach that could be used to treat your client, such as client-centered therapy . Provide information on the type of treatment you chose, the client's reaction to the treatment, and the end result of this approach. Explain why the treatment was successful or unsuccessful.
• Psychoanalytic approach : Describe how a psychoanalytic therapist would view the client's problem. Provide some background on the psychoanalytic approach and cite relevant references. Explain how psychoanalytic therapy would be used to treat the client, how the client would respond to therapy, and the effectiveness of this treatment approach.
• Pharmacological approach : If treatment primarily involves the use of medications, explain which medications were used and why. Provide background on the effectiveness of these medications and how monotherapy may compare with an approach that combines medications with therapy or other treatments.

This section of a case study should also include information about the treatment goals, process, and outcomes.

When you are writing a case study, you should also include a section where you discuss the case study itself, including the strengths and limitiations of the study. You should note how the findings of your case study might support previous research. 

In your discussion section, you should also describe some of the implications of your case study. What ideas or findings might require further exploration? How might researchers go about exploring some of these questions in additional studies?

Need More Tips?

Here are a few additional pointers to keep in mind when formatting your case study:

• Never refer to the subject of your case study as "the client." Instead, use their name or a pseudonym.
• Read examples of case studies to gain an idea about the style and format.
• Remember to use APA format when citing references .

Crowe S, Cresswell K, Robertson A, Huby G, Avery A, Sheikh A. The case study approach .  BMC Med Res Methodol . 2011;11:100.

Crowe S, Cresswell K, Robertson A, Huby G, Avery A, Sheikh A. The case study approach . BMC Med Res Methodol . 2011 Jun 27;11:100. doi:10.1186/1471-2288-11-100

Gagnon, Yves-Chantal.  The Case Study as Research Method: A Practical Handbook . Canada, Chicago Review Press Incorporated DBA Independent Pub Group, 2010.

Yin, Robert K. Case Study Research and Applications: Design and Methods . United States, SAGE Publications, 2017.

By Kendra Cherry, MSEd Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."

Psychology’s 10 Greatest Case Studies – Digested

These ten characters have all had a huge influence on psychology and their stories continue to intrigue each new generation of students.

27 November 2015

By Christian Jarrett

These ten characters have all had a huge influence on psychology and their stories continue to intrigue each new generation of students. What's particularly fascinating is that many of their stories continue to evolve – new evidence comes to light, or new technologies are brought to bear, changing how the cases are interpreted and understood. What many of these 10 also have in common is that they speak to some of the perennial debates in psychology, about personality and identity, nature and nurture, and the links between mind and body.

Phineas Gage

One day in 1848 in Central Vermont, Phineas Gage was tamping explosives into the ground to prepare the way for a new railway line when he had a terrible accident. The detonation went off prematurely, and his tamping iron shot into his face, through his brain, and out the top of his head. Remarkably Gage survived, although his friends and family reportedly felt he was changed so profoundly (becoming listless and aggressive) that "he was no longer Gage."

There the story used to rest – a classic example of frontal brain damage affecting personality. However, recent years have seen  a drastic reevaluation  of Gage's story in light of new evidence. It's now believed that he underwent significant rehabilitation and in fact began work as a horse carriage driver in Chile. A  simulation of his injuries  suggested much of his right frontal cortex was likely spared, and  photographic evidence  has been unearthed showing a post-accident dapper Gage. Not that you'll find this revised account in many psychology textbooks:  a recent analysis  showed that few of them have kept up to date with the new evidence.

See also Jim Horne's ' Blasts from the past ', looking back at similar accounts from the era.

Henry Gustav Molaison (known for years as H.M. in the literature to protect his privacy), who died in 2008, developed severe amnesia at age 27 after undergoing brain surgery as a form of treatment for the epilepsy he'd suffered since childhood. He was subsequently the focus of study by over 100 psychologists and neuroscientists and he's been mentioned in over 12,000 journal articles! Molaison's surgery involved the removal of large parts of the hippocampus on both sides of his brain and the result was that he was almost entirely unable to store any new information in long-term memory (there were some exceptions – for example, after 1963 he was aware that a US president had been assassinated in Dallas). The extremity of Molaison's deficits was a surprise to experts of the day because many of them believed that memory was distributed throughout the cerebral cortex.

Today, Molaison's legacy lives on: his brain was carefully sliced and preserved and turned into a 3D digital atlas and his life story is reportedly due to be turned into a feature film based on the book researcher Suzanne Corkin wrote about him:  Permanent Present Tense, The Man With No Memory and What He Taught The World .

See also 'Understanding amnesia - Is it time to forget H.M.?'

Victor Leborgne (nickname "Tan")

The fact that, in most people, language function is served predominantly by the left frontal cortex has today almost become common knowledge, at least among psych students. However, back in the early 19th century, the consensus view was that language function (like memory, see entry for H.M.) was distributed through the brain. An 19th century patient who helped change that was Victor Leborgne, a Frenchman who was nicknamed "Tan" because that was the only sound he could utter (besides the expletive phrase "sacre nom de Dieu").

In 1861, aged 51, Leborgne was referred to the renowned neurologist Paul Broca, but died soon after. Broca examined Leborgne's brain and noticed a lesion in his left frontal lobe – a segment of tissue now known as Broca's area. Given Leborgne's impaired speech but intact comprehension, Broca concluded that this area of the brain was responsible for speech production and he set about persuading his peers of this fact – now recognised as a key moment in psychology's history.

For decades little was known about Leborgne, besides his important contribution to science. However, in a paper published in 2013, Cezary Domanski at Maria Curie-Sklodowska University in Poland uncovered new biographical details, including the possibility that Leborgne muttered the word "Tan" because his birthplace of Moret, home to several tanneries.

See also ' Glimpsed at last ', and ' Using brain imaging to re-evaluate psychology's three most famous cases '.

Wild Boy of Aveyron

The "Wild boy of Aveyron" – named Victor by the physician Jean-Marc Itard – was found emerging from Aveyron forest in South West France in 1800, aged 11 or 12, where's it's thought he had been living in the wild for several years. For psychologists and philosophers, Victor became a kind of "natural experiment" into the question of nature and nurture. How would he be affected by the lack of human input early in his life?

Those who hoped Victor would support the notion of the "noble savage" uncorrupted by modern civilisation were largely disappointed: the boy was dirty and dishevelled, defecated where he stood and apparently motivated largely by hunger. Victor acquired celebrity status after he was transported to Paris and Itard began a mission to teach and socialise the "feral child". This programme met with mixed success: Victor never learned to speak fluently, but he dressed, learned civil toilet habits, could write a few letters and acquired some very basic language comprehension. Autism expert Uta Frith believes Victor may have been abandoned because he was autistic, but she acknowledges we will never know the truth of his background.

Victor's story inspired the 2004 novel  The Wild Boy  and was dramatised in the 1970 French film  The Wild Child .

Listen to an episode of 'The Mind Changers'.

Nicknamed 'Kim-puter' by his friends, Peek who died in 2010 aged 58, was the inspiration for Dustin Hoffman's autistic savant character in the multi-Oscar-winning film  Rain Man . Before that movie, which was released in 1988, few people had heard of autism, so Peek via the film can be credited with helping to raise the profile of the condition.

Arguably though, the film also helped spread the popular misconception that giftedness is a hallmark of autism (in one notable scene, Hoffman's character deduces in an instant the precise number of cocktail sticks – 246 – that a waitress drops on the floor). Peek himself was actually a non-autistic savant, born with brain abnormalities including a malformed cerebellum and an absent corpus callosum (the massive bundle of tissue that usually connects the two hemispheres). His savant skills were astonishing and included calendar calculation, as well as an encyclopaedic knowledge of history, literature, classical music, US zip codes and travel routes. It was estimated that he read more than 12,000 books in his life time, all of them committed to flawless memory. Although outgoing and sociable, Peek had coordination problems and struggled with abstract or conceptual thinking.

"Anna O." is the pseudonym for Bertha Pappenheim, a pioneering German Jewish feminist and social worker who died in 1936 aged 77. As Anna O. she is known as one of the first ever patients to undergo psychoanalysis and her case inspired much of Freud's thinking on mental illness. Pappenheim first came to the attention of another psychoanalyst, Joseph Breuer, in 1880 when he was called to her house in Vienna where she was lying in bed, almost entirely paralysed. Her other symptoms include hallucinations, personality changes and rambling speech, but doctors could find no physical cause.

For 18 months, Breuer visited her almost daily and talked to her about her thoughts and feelings, including her grief for her father, and the more she talked, the more her symptoms seemed to fade – this was apparently one of the first ever instances of psychoanalysis or "the talking cure", although the degree of Breuer's success has been disputed and some historians allege that Pappenheim did have an organic illness, such as epilepsy.

Although Freud never met Pappenheim, he wrote about her case, including the notion that she had a hysterical pregnancy, although this too is disputed. The latter part of Pappenheim's life in Germany post 1888 is as remarkable as her time as Anna O. She became a prolific writer and social pioneer, including authoring stories, plays, and translating seminal texts, and she founded social clubs for Jewish women, worked in orphanages and founded the German Federation of Jewish Women.

Kitty Genovese

Sadly, it is not really Kitty Genovese the person who has become one of psychology's classic case studies, but rather the terrible fate that befell her. In 1964 in New York, Genovese was returning home from her job as a bar maid when she was attacked and eventually murdered by Winston Mosely. What made this tragedy so influential to psychology was that it inspired research into what became known as the Bystander Phenomenon – the now well-established finding that our sense of individual responsibility is diluted by the presence of other people. According to folklore, 38 people watched Genovese's demise yet not one of them did anything to help, apparently a terrible real life instance of the Bystander Effect.

However, the story doesn't end there because historians have since established  the reality was much more complicated  – at least two people did try to summon help, and actually there was only one witness the second and fatal attack. While the main principle of the Bystander Effect has stood the test of time, modern psychology's understanding of the way it works has become a lot more nuanced. For example, there's evidence that in some situations people are more likely to act when they're part of a larger group, such as when they and the other group members all belong to the same social category (such as all being women) as the victim.

See also another angle , on false confessions.

Little Albert

"Little Albert" was the nickname that the pioneering behaviourist psychologist John Watson gave to an 11-month-old baby, in whom, with his colleague and future wife Rosalind Rayner, he deliberately attempted to instill certain fears through a process of conditioning. The research, which was of dubious scientific quality, was conducted in 1920 and has become notorious for being so unethical (such a procedure would never be given approval in modern university settings).

Interest in Little Albert has reignited in recent years as an academic quarrel has erupted over his true identity. A group led by Hall Beck at Appalachian University announced in 2011 that they thought Little Albert was actually Douglas Merritte, the son of a wet nurse at John Hopkins University where Watson and Rayner were based. According to this sad account, Little Albert was neurologically impaired, compounding the unethical nature of the Watson/Rayner research, and he died aged six of  hydrocephalus (fluid on the brain).

However, this account was challenged by a different group of scholars led by Russell Powell at MacEwan University in 2014. They established that Little Albert was more likely William A Barger (recorded in his medical file as Albert Barger), the son of a different wet nurse. Earlier this year, textbook writer Richard Griggs weighed up all the evidence and concluded that the Barger story is the more credible, which would mean that Little Albert in fact died 2007 aged 87.

Chris Sizemore

Chris Costner Sizemore is one of the most famous patients to be given the controversial diagnosis of multiple personality disorder, known today as dissociative identity disorder. Sizemore's alter egos apparently included Eve White, Eve Black, Jane and many others. By some accounts, Sizemore expressed these personalities as a coping mechanism in the face of traumas she experienced in childhood, including seeing her mother badly injured and a man sawn in half at a lumber mill.

In recent years, Sizemore has described how her alter egos have been combined into one united personality for many decades, but she still sees different aspects of her past as belonging to her different personalities. For example, she has stated that her husband was married to Eve White (not her), and that Eve White is the mother of her first daughter. Her story was turned into a movie in 1957 called  The Three Faces of Eve  (based on a book of the same name written by her psychiatrists). Joanne Woodward won the best actress Oscar for portraying Sizemore and her various personalities in this film. Sizemore published her autobiography in 1977 called  I'm Eve . In 2009, she appeared on the BBC's  Hard Talk  interview show.

David Reimer

One of the most famous patients in psychology, Reimer lost his penis in a botched circumcision operation when he was just 8 months old. His parents were subsequently advised by psychologist John Money to raise Reimer as a girl, "Brenda", and for him to undergo further surgery and hormone treatment to assist his gender reassignment. Money initially described the experiment (no one had tried anything like this before) as a huge success that appeared to support his belief in the important role of socialisation, rather than innate factors, in children's gender identity.

In fact, the reassignment was seriously problematic and Reimer's boyishness was never far beneath the surface. When he was aged 14, Reimer was told the truth about his past and set about reversing the gender reassignment process to become male again. He later campaigned against other children with genital injuries being gender reassigned in the way that he had been. His story was turned into the book  As Nature Made Him, The Boy Who Was Raised As A Girl  by John Colapinto, and he is the subject of two BBC Horizon documentaries. Tragically, Reimer took his own life in 2004, aged just 38.

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